The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
David J. Whitehouse - One of the best experts on this subject based on the ideXlab platform.
-
Stiffness estimation of a parallel kinematic Machine
Science China-technological Sciences, 2001Co-Authors: Tian Huang, Xingyu Zhao, Lihua Zhou, Dawei Zhang, Ziping Zeng, David J. WhitehouseAbstract:This paper presents a simple yet comprehensive approach to quickly estimating the Stiffness of a tripod-based parallel kinematic Machine. This approach can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved by linear superposition. The 3D representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The result is compared with that obtained through finite element analysis.
-
Stiffness estimation of a tripod based parallel kinematic Machine
International Conference on Robotics and Automation, 2001Co-Authors: Tian Huang, X Y Zhao, L H Zhou, D W Zhang, Z P Zeng, David J. WhitehouseAbstract:Presents a simple yet comprehensive approach that enables the Stiffness of a tripod-based parallel kinematic Machine to be quickly estimated. The approach arises from the basic idea for the determination of the equivalent Stiffness of a group of serially connected linear springs and can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of the virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved via linear superposition. The three-dimensional representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The results are compared with those obtained through experiments.
-
ICRA - Stiffness estimation of a tripod-based parallel kinematic Machine
IEEE Transactions on Robotics and Automation, 2001Co-Authors: Tian Huang, X Y Zhao, L H Zhou, D W Zhang, Z P Zeng, David J. WhitehouseAbstract:Presents a simple yet comprehensive approach that enables the Stiffness of a tripod-based parallel kinematic Machine to be quickly estimated. The approach arises from the basic idea for the determination of the equivalent Stiffness of a group of serially connected linear springs and can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of the virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved via linear superposition. The three-dimensional representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The results are compared with those obtained through experiments.
M Kimchi - One of the best experts on this subject based on the ideXlab platform.
-
Influence of welding Machine mechanical characteristics on the resistance spot welding process and weld quality
Welding Journal, 2003Co-Authors: H Tang, Hongyan Zhang, S J Hu, Z Feng, M KimchiAbstract:Mechanical characteristics of resistance spot welding Machines, such as Stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are explored by analyzing process signatures, such as welding force and electrode displacement, and other process characteristics, such as electrode alignment. A better understanding of the influences is achieved through this analysis. This study shows Machine Stiffness and friction affect welding processes and weld quality. It also confirms the moving mass does not significantly affect the process and quality of resistance spot welding.
-
influence of welding Machine mechanical characteristics on the resistance spot welding process and weld quality how Machine Stiffness friction and moving mass can affect welding results
2003Co-Authors: H Tang, S J Hu, Z Feng, M KimchiAbstract:116 ABSTRACT. Mechanical characteristics of resistance spot welding Machines, such as Stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are ex- plored by analyzing process signatures, such as welding force and electrode dis- placement, and other process characteris- tics, such as electrode alignment. A better understanding of the influences is achieved through this analysis. This study shows Machine Stiffness and friction affect welding processes and weld quality. It also confirms the moving mass does not signif- icantly affect the process and quality of re- sistance spot welding.
Fulun Yang - One of the best experts on this subject based on the ideXlab platform.
-
Stock removal rate and workpiece strength in multi-pass grinding of ceramics
Journal of Materials Processing Technology, 2000Co-Authors: Bi Zhang, Fulun Yang, Jiexin Wang, Richard MonahanAbstract:Abstract Stock removal rate and workpiece strength are evaluated in terms of Machine Stiffness and grinding wheel parameters in multi-pass grinding of silicon nitride ceramics. This paper presents theoretical analyses on normal grinding force, actual depth of cut (ADOC) of a grinding wheel, stock removal rate and residual strength of ground workpieces, as well as experimental results to verify the analyses. In the grinding experiments, silicon nitride workpieces are subjected to multi-pass grinding with four diamond wheels of three grit sizes and two bond types, as well as a precision grinder of adjustable Stiffness. The electrolytic in-process dressing (ELID) technique is adopted to evaluate how wheel dressing can affect the workpiece strength and stock removal rate in multi-pass grinding. A discussion addresses the issues of strength gain and strength loss for ground workpieces and a recommendation is provided to obtain higher residual strength of ground workpiece.
-
The Effect of Grinding Machine Stiffness on Surface Integrity of Silicon Nitride
Journal of Manufacturing Science and Engineering-transactions of The Asme, 2000Co-Authors: Fulun Yang, Bi Zhang, Jiexin Wang, Richard MonahanAbstract:A theoretical model based on mechanics and Machine dynamics is presented to describe the effect of Machine Stiffness on surface integrity of ground silicon nitride. The model accounts for both the static and dynamic structural loop Stiffnesses of a precision-grinding Machine. Experimental results are also presented to verify the model. A unique workholder with an adjustable compliance is used to achieve a structural loop Stiffness in the range of 5-40 N/μm. Silicon nitride is ground with cup-type diamond wheels of vitrified and cast iron fiber bonds. To effectively stabilize the cutting performance of a cast iron fiber bond wheel, the ELID technique is adopted for in-process dressing. The damage depth of ground workpieces is assessed against Machine Stiffness. The modeling and experimental results demonstrate that there exists a critical Machine Stiffness in grinding of ceramics. When Machine Stiffness is higher than the critical Stiffness, no chatter should occur in the grinding process. In this case, damage depth increases with the increase of set depth of cut. In contrast, if Machine Stiffness is lower than the critical Stiffness, chatter can occur in the grinding process that may induce grinding damage. The model can also be used to predict the critical Machine Stiffness for other types of structural ceramics.
-
Residual stress and damage effect on integrity of ground silicon nitride
Journal of Materials Science, 2000Co-Authors: R. W. Monahan, Fulun Yang, Bi Zhang, Jiexin WangAbstract:Ceramic workpiece integrity and residual surface stresses generated by single pass diamond grinding were evaluated for three flaring cup wheels and four Machine-loop Stiffnesses. Stresses in silicon nitride bars ground on one face were characterized by X-ray diffraction, strength by four-point bending, and grinding damage depth by scanning electron microscopy. A custom-built workpiece holder was used to tune the grinding Machine-loop Stiffness. Electrolytic in-process dressing was applied to one of the wheels to provide stable cutting conditions. The experimental results indicate Machine Stiffness does not have significant influence on flexural strength, but rather affects the depth of cut. All ground surfaces have some degree of damage and residual stress, and differences are revealed between wheel bonds and grit sizes. The competing phenomena of strength enhancement due to residual stress and strength degradation due to damage are discussed.
-
the effect of Machine Stiffness on grinding of silicon nitride
International Journal of Machine Tools & Manufacture, 1999Co-Authors: Bi Zhang, Jiexin Wang, Fulun YangAbstract:This study investigates the effect of Machine Stiffness on normal forces, actual depth of cut, and workpiece strength in grinding of silicon nitride. To obtain a grinding system with an adjustable Stiffness, a compliant workholder is added to a precision grinder. Single-pass and multi-pass grinding experiments are conducted to evaluate the effect of Machine Stiffness. Cup-type diamond wheels of two different bond types and three grit sizes are used in the grinding experiments. Static and dynamic simulation is carried out to correlate grinding forces and actual depth of cut with Machine Stiffness. Since the simulation uses a time-domain model, it can accommodate non-linearities caused by the effect of Machine Stiffness on grinding forces and actual wheel depth of cut, workpiece regeneration, wheel wear, as well as wheel bond type and grit size effects, etc. Particularly, the model allows simulating grinding instability and the interference phenomenon due to residual material removal in multi-pass grinding. The study concludes that both simulation and experimental results have a good agreement.
Tian Huang - One of the best experts on this subject based on the ideXlab platform.
-
Stiffness estimation of a parallel kinematic Machine
Science China-technological Sciences, 2001Co-Authors: Tian Huang, Xingyu Zhao, Lihua Zhou, Dawei Zhang, Ziping Zeng, David J. WhitehouseAbstract:This paper presents a simple yet comprehensive approach to quickly estimating the Stiffness of a tripod-based parallel kinematic Machine. This approach can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved by linear superposition. The 3D representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The result is compared with that obtained through finite element analysis.
-
Stiffness estimation of a tripod based parallel kinematic Machine
International Conference on Robotics and Automation, 2001Co-Authors: Tian Huang, X Y Zhao, L H Zhou, D W Zhang, Z P Zeng, David J. WhitehouseAbstract:Presents a simple yet comprehensive approach that enables the Stiffness of a tripod-based parallel kinematic Machine to be quickly estimated. The approach arises from the basic idea for the determination of the equivalent Stiffness of a group of serially connected linear springs and can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of the virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved via linear superposition. The three-dimensional representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The results are compared with those obtained through experiments.
-
ICRA - Stiffness estimation of a tripod-based parallel kinematic Machine
IEEE Transactions on Robotics and Automation, 2001Co-Authors: Tian Huang, X Y Zhao, L H Zhou, D W Zhang, Z P Zeng, David J. WhitehouseAbstract:Presents a simple yet comprehensive approach that enables the Stiffness of a tripod-based parallel kinematic Machine to be quickly estimated. The approach arises from the basic idea for the determination of the equivalent Stiffness of a group of serially connected linear springs and can be implemented in two steps. In the first step, the Machine structure is decomposed into two substructures associated with the Machine frame and parallel mechanism. The Stiffness models of these two substructures are formulated by means of the virtual work principle. This is followed by the second step that enables the Stiffness model of the Machine structure as a whole to be achieved via linear superposition. The three-dimensional representations of the Machine Stiffness within the usable workspace are depicted and the contributions of different component rigidities to the Machine Stiffness are discussed. The results are compared with those obtained through experiments.
H Tang - One of the best experts on this subject based on the ideXlab platform.
-
Influence of welding Machine mechanical characteristics on the resistance spot welding process and weld quality
Welding Journal, 2003Co-Authors: H Tang, Hongyan Zhang, S J Hu, Z Feng, M KimchiAbstract:Mechanical characteristics of resistance spot welding Machines, such as Stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are explored by analyzing process signatures, such as welding force and electrode displacement, and other process characteristics, such as electrode alignment. A better understanding of the influences is achieved through this analysis. This study shows Machine Stiffness and friction affect welding processes and weld quality. It also confirms the moving mass does not significantly affect the process and quality of resistance spot welding.
-
influence of welding Machine mechanical characteristics on the resistance spot welding process and weld quality how Machine Stiffness friction and moving mass can affect welding results
2003Co-Authors: H Tang, S J Hu, Z Feng, M KimchiAbstract:116 ABSTRACT. Mechanical characteristics of resistance spot welding Machines, such as Stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are ex- plored by analyzing process signatures, such as welding force and electrode dis- placement, and other process characteris- tics, such as electrode alignment. A better understanding of the influences is achieved through this analysis. This study shows Machine Stiffness and friction affect welding processes and weld quality. It also confirms the moving mass does not signif- icantly affect the process and quality of re- sistance spot welding.
